The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 03, 2015
Filed:
Nov. 04, 2011
Shinji Okada, Gunma, JP;
Hideyuki Kobayashi, Gunma, JP;
Naoki Sawada, Gunma, JP;
NSK Ltd., Tokyo, JP;
Abstract
[Problem] An object of the present invention is to provide an electric power steering apparatus that realizes weight saving and downsizing of component parts by counting and controlling the number of times of end hitting and simultaneously calculating a current limit value depending on the number of times of end hitting to limit assist. [Means for solving the problem] The present invention is an electric power steering apparatus that comprises an end hitting detection means that detects end hitting based on the steering torque and a differential steering torque obtained by differentiating the steering torque and outputs an end hitting detection signal, a counting means that counts a number 1 of times of end hitting detected by the end hitting detection means, a storage means that stores and keeps a total number of times of end hitting, and a current limit value calculating means that calculates a current limit value depending on a number 2 of times of end hitting obtained by adding the number 1 of times of end hitting from the counting means and the total number of times of end hitting from the storage means, wherein the current command value is limited based on the current limit value calculated by the current limit value calculating means.